Metal complexes of pyrazole-haloketones and preparation thereof



n te S e P tent ffice Patented August 9, 1966 3 265,705 METAL COMPLEXE FPYRAZOLE-HALOKE- TONES AND PREPARATION THEREOF WaltcrMahler, Wilmington,Del nssignor to E. l. du Pont de Nemours and Company, Wilmington, Del.,a corporation of Delaware. No Drawing. Filed Juno 9, 19 65, Ser. No.462,721

I 11 Claims. (Cl. 260-299) This invention relates to anew class oforgano-inorganic coordination compounds and a process for theirpreparation. More particularly, the invention relates to chclatecomplexes of pyrazole, haloalkylketoncs, and selected metals.

The compounds of this invention may be represented by the generalformula /N'N\ 1 mam) a a wherein R; and R, each are selected from thegroup conlit sisting of perhaloalk-yl and w hydroperhaloalkyl, eachhavability of the element, with the proviso that when the andsubatmosphcric as well as superatmospheric pressures may be utilized inaddition to atmospheric pressure. Thus, pressures of 1 mm. of mercury to50 atmospheres are operable herein. At pressures below or aboveatmospheric pressure, however, it is desirable to operate in a closedsystem to prevent loss of reactants.

Although a solvent or inert diluent may be employed, the reaction mayequally well be carried out in the presence of the necessary reactantswithout added di-luents. The molar ratio of metal pyrazolidc toketonemay be varied widely, for example, between molar ratios of about1:20 to about 20:]. Generally, the reactants are employed inapproximatciy stoi-chiometric quantitics, although when it is desirableto ensure maintenance of a liquid reaction medium. a slight molar excessof the ketone is introduced into the reaction mixture. t

The metal pymzolides which are employed as reactants herein are preparedby contacting and reacting a solution of the appropriate metal salt withpyrazole in the presence of a base. Altcrnately. the metal pyrozolidcmay be produced by first contacting pyrazole with an alkali metal andsubsequently reacting the thus formed alkali metal pyrazolidc with theappropriate metal salt. The metal pyrazolidc may be preparedindependently and utilized herein or it may be prepared in situ justprior to the addition of the haloalkylketone.

element has an atomicnumberof 74-or 92, his in the form of its oxide W0or'UO respectively; 2 is one.

'half the coordination number of M; vis the valence state of M and is1-4 preferably 1-3 and (z- -v) is 0 or 1. In the formula as shown thecircle within the pyrazole nucleus represents all the resonant forms ofthis structurc'. This resonance stabilization isbelieved to account foror at least enhance the stability of the complexes. Althoughthecoordination numbers of the metals operable herein vary from 2-8, mostfrequently the coordination numbers are the even numbers within thisrange, and especially the even numbers 4 and 6. Hence, 2 in theaforesaid formula generally will be 1-4, with 2-3 being preferable. Inthe preferred complexes M is an element having an atomic number lyingwithin one of the ranges 21-30 and 39-46, and espeeially 26-30, and thehalogens in R, and R, are fluorine or chlorine] More preferably, each R,and R, should contain at least one fluorine atom, and R, and R, takentogether should contain at least two fluorine atoms. Of highestpreferability are the aforesaid R and R, groupswhich'contain at leastdouble this number of fluorine atoms.

The novel complexes of this invention are prepared 'by the reaction of ametal pyrazolide with a di(haloalkyl) or haloalkylene ketone. The ketonemay be employed as the free ketone or as one of its solvates, such as ahydrate or an alcoholate. The reaction by which the complexes areprepared'may be represented by the fol-. lowing simplified equation inthe range of 0 to 200? C. are employed, with a temi In the generalformula representing the chelate complexes of this invention it may beseen that the complex may be protonated, i.e., when (z-v) is l, in whichcase the expression ''(z--v) indicates that the portion of the complexshown within the outer brackets has a negative charge. The source of theproton generally is the pyrazole reactant. in which case the pyrazolidenucleus enters the chelate complex along with an additional molecule ofhaloalkylketonef of reaction, which probably occurs to enable the metalto achieve a more stable coordination number, may be represented by theequation Although it is not fully understood how the proton is bonded tothe complex, it is believed that the proton is plexes it has been notedthat the compounds of' this invention may be solvated with aconventional solvating agent such as water, an alcohol, ammonia andthelike,

as well asthe pyrazole or the haloalkyl ketone utilized as a reactant.

The following examples are intended to illustrate, but not limit, thepresent invention. In the examples parts are by weight.

Fifty parts of pyrnzole is heated until molten C.) and five parts ofsodium metal is added in small portions. Ten parts of anhydrous ferricchloride is 'added with stirring. The reaction mixture is cooledandwashed with methanol. The insoluble. portion is contacted with 30 partsof hexafiuoroacctone-LSH O. This mixture is filtered and the filtratediluted with water to give a precipitate which is suhlimed in vacuum atC. The sublimate'is crystallized from benzene to give 5 parts ofvcry'pale green needles, M.P. 231 C. The analysis corresponds toFctpyrazolide-her afluoroncetone) This more complicated type a 3 AflU!)Sl S.-CalCLi. 1'01 C1 H9F13N 03Fe: C, H, 9; F, 45.31; N, 11.13; Fe,7.40. Found: C, 28.65;

1.29; F, 45.57; N, 12.23; Fe, 7.37.

Six parts of nickel bispyrazolide-H O is stirred with parts ofhexafiuoroacetone-lfil-l O. The green soion is filtered. The filtrate isevaporated in a stream nitrogen and the resulting green solidrecrystallized im hot toluene to give 14 parts of fine green needles,.1. 143 C. The analysis corresponds to[nickel(pyrazdchcxalluotoacetonehl"-H H O. Analyst'.t.-Calcd. for C H FN Q Ni: C, 27.84; H, 55; F, 44.08; N, 10.83; Ni, 7.57. Found: C, 28.04;1.52; F, 42.82; N, 10.44; Ni, 7.60.

tample 3.--[Nicke1 tris(pyrazolide-dichlorotetrafluoroacetone) ]--H -H OTen parts of nickel(pyrazolide) is contacted with 30 .rtsdichlorotetrafluoroacetone-H 0. The solid goes to solution and isprecipitated by adding 100 parts 11 d isolated by filtration. This istaken up in 50 parts hot benzene, cooled, and reprecipitated with 300.parts troleum ether. The resulting green crystals melt at 0 C. and havea composition corresponding to [Nirazolidc-dichlorotetralluoroacctone)]H -H O. AI1l1[ )SlS.--C3 Cd. for CmH ClgFuNqOQNlI F, 24.31; Ni, 6.71.Found: F, 25.88; Cl, 23.87; Ni, 49.

xamplc 4.C0ppcr bis(pyrazolide-lzexafluoroacetone) Part A.-Fifteen partsof cupric bispyrazolide-NH is rred with 25 parts ofhCXHfiUOI'OiiCClOHCI-SH O for 30 inutes. The resulting solution ispoured into 1000 parts water to give 38 parts ofCu(pyrazolide-hexafiuoroacene) This product is purified by subliming at70 C. 1d recrystallizing from benzene; M.P. l57-160 C. ealed tube).

AnUl).l'iS.--C31Cd. for CIQHQFIQNQOQCU: C, H, 13; F, 43.10; N, 10.58;Cu, 12.01. Found: C, 27.68; 1.38; F, 43.36; N, 10.65; Cu, 12.05.

Part B.-Four parts of cupric bispyrazolide is combined lth eight partsof gaseous hexafluoroacetone in a sealed be and kept at 100 C. for fourhours. On cooling,

1 parts of Cu(pyrazolide-he'xafiuoroacetone) is obtained blue crystals,M.P. 160 C., having the same infrared ittern as the product obtained inPart A.

xample 5 .C0ppcr bi.r(pyrazolide-dichloroteIrafluoroacetone)-die/1lorotctrafluoroacetone xample 6.--Copperbr's(pyrazolide-telrachlorodtfluoroacetone) Ten parts of cupricbispyrazolide is mixed with 30 parts tetrachlorodifiuoroacetone, (CClF)CO, at 25 C. fter 30 minutes, the mixture is taken up in 150 parts of1m benzene and filtered. The filtrate. is concentrated d the 22 parts ofblue crystals collected have a melting int of 141 C. and correspond toCu('pyrazolide-tetralorodifluoroacetone) Anulysis.-Calcd. forCmClaHgFqNqOzCUi C, 9.6. iund: Cu, 9.70.

Five parts of cupric bispyrazolide is mixed with 20 parts ofchloropentafiuoroacetone, CF COCCIF and heated to 100 C. for 30 minutes.The resulting blue solid is dissolved in 100 parts of warm benzene,filtered, and the filtrate is concentrated to give 12 parts of bluecrystals that have a melting point of 136 C. The cotraositioncorresponds to Cu(pyrazolide-chloropentafiuoroac :tone)- Analysis.Calcd.for C Cl H F N O Cu: Cu, 11.3. 1

Found: Cu, 11.06.

Example 8.--C0ppcr hist 1yrazolirlc-triclrlorotrifluoroacetone) parts ofhexafluorocyclobutanonc in a closed cylinder at 100 C. for one hour. Thetube is opened, unreacted .hexafiuorocyclobutanone is vented, and bluecrystals,

M.P. 186 C., are recoveredand found to be cupric bis-(pyrazolide-hexafiuorocyclobutanone).

Analysis.--Calcd. for C H F N O Cu: C. 30 38: H, 1.09; F, 41.23; N,10.12: Cu. 11.47. Found: C, 30.49; H, 1.34; F, 41.92; N, 9.56; Cu,10.82.

Example 10.-Zinc tris(pyrazolidehexafluoroacerone) -H Twenty parts ofZn(pyrazolide) is dissolved in parts of warm C.) hexafluoroacetone-1.5110. On standing two hours white crystals deposit. M.P. 105 C.; theanalysis corresponds to [Zn(pyrazolide-hexafluoroacetone)3]'H+.

' Analysis.Calcd. for C H F N O Zn: C, 28.26; H, 2.00; F, 44.73; N,10.98: Zn. 8.56. .Foundz'C, 28.54; H, 1.81; F, 43.37; N, 12.42; Zn,8.32.

Example I1.Silvcr pyrazolidc-ltexafluoroacetone Fifteen parts of silverpyrazolide is contacted with 60 parts of hexafluoroacetone-lfiH O. Allthe solid dissolves; from the solution on cooling is recoveredAg(pyrazolide-hexafluoroacctone). This chelate complex, as is the goldanalogue, is of limited stability.

Example I 2.C0balt tris(pyrazolide-ltexafluoroacetone) To 10 parts ofCoCl as a solution in aqueous ammonia is added a solution of 20 parts ofpyrazole in aqueous ammonia. This gives a purple precipitate which isisolated by filtering under nitrogen. This solid is contacted with 25parts of hexafluoroacetone-L5H O. The liquid material is filtered offand the solid product extracted with benzene and recrystallized to give8 parts of Co(pyrazolide-hexafiuoroacetone) M.P. 112 C. During thecourse of this experiment the cobalt has been oxidized from a valencestate of two to a valence state of three.

Analysis.-Calcd. for H F N O Coz C, 28.50; H, 1.19; F, 45.12; N, 11.08;Co. 7.78. Found: C, 28.05; H, 1.52; F, 42.82; N, 10.44; Co, 7.60.

Example ]3.Tl|orium tetrakr's(pyrazolideltexafluoroacetone) Ten parts ofthorium nitrate is dissolved in parts of H 0 to which is added 30'partsof pyrazole in 100 parts of H 0. To this solution is added aqueousammonia to give a white precipitate which is isolated by filtration andtreated with 20 parts of hexafiuoroacetone-CH OH. Excess reagent isevaporated on a steam bath with a stream of nitrogen in two hours.mainder is extracted with hot benzene and filtered. The filtrate istaken to dryness on a steam bath to give The refor thecorrespondingreactant in column 2 in the procedure of the exampleindicated in column 3, the product shown in column 4 is obtained. as anabbreviation of pyrazolide.

In this table Pz is used Th(pyrazolide-hexafiuoroacetone) in the form ofa white solid which sublimes at 180 C. and melts at 242 C.

AnaIysis.--Calcd. for C 4H12F 4NgO ThI C, H, 1.03; F, 39.18; N, 9.62;Th, 19.95. Found: C, 25.02; H, 1.38; F, 38.91; N, 9.62; Th, 20.39.

Example 14.- [Europium retrakis(py razolide- Izexafluoroacetone) 1* H+pyrazole To parts of liquid pyrazole (70 C.) is added six parts ofpotassium metal in small portions. The mixture is allowed to cool and 10parts of anhydrous EuCl is stirred into the solid after which 50 partsof methanol is added and the mixture is filtered. The solid is extractedwith hexafiuoroacetone-CH OH. On dilution of the filtrate with 100 partsof water, a white precipitate forms which, after recrystallization fromcyclohexane, has an M.P. of 145-l50 C. The solid as well as solutionsthereof in hexane or benzene exhibit red fluorescence under ultravioletlight. The composition corresponds to [En pyrazolide-hexafiuoroacetoneH+ pyrazole.

Analysis.Calcd. for C27H17F24N1004EU: C, 28.12; H, 1.39; N, 12.15; Eu,13.19. Found: C, 28.96; H, 1.77; N, 12.55; Eu, 12.57.

Example ]5.Uranyl is(pyrazolide-hexafluoroacetone) hexaflizoroacetone-Nl-l Ten parts of uranyl acetate is dissolved in 100 parts of water andadded to a solution of twenty parts pyrazole in 200 parts of aqueousammonia. The resulting yellow precipitate is contacted with 30 partshexafiuoroacetone-methanol at 25 C. for two hours. The excesshexafluoroacetone-methanol is evaporated in a stream of nitrogen and theremaining solid extracted with benzene in a Soxhlet apparatus. In thisway -5 parts of yellow crystals is obtained with acompositioncorresponding to U0 (pyrazolidehexafiuoroacetone) -hexafiuoroacetone NH;

Arzalysis.Calcd. for C H F N O U: C, 19.57; H, 1.0; F, 37.18; N, 7.61;U, 25.88. Found: C, 19.83; H, 1.52; F, 36.77; N, 8.10; U, 26.93.

Further examples of the process and products of this invention aresummarized in Table I. When the fluoroketone or metal salt indicated incolumn 1 is substituted The pyrazolide-haloalkylketone-metal complexesof this invention are especially useful as antistatic agents forpolymeric materials, and particularly polyamides. For example, byincorporating a small quantity, such as 23 weight percent, of one ofthese complexes into nylon yarn, the electrical conductivity of the yarnis increased more than a thousandfold. The following example utilizing acommercially available 66 nylon (from hexamethylene diamine and adipicacid) demonstrates this utility.

Example A Two parts of cupric bis(pyrazolide-hexafluoroacetone) isblended with parts ny lon 66 at 283 C. (melt) for 30 minutes. The blendis spun and the yarns drawn and the resistivity measured to be 10 ohms.The unmodified nylon 66 has a resistivity of 10 ohms. For comparison,cotton, which is considered to be acceptable, has a value of 10 ohms.

Example A is repeated with zinc tris(pyrazolide-hexafluoroacetone) beingemployed in place of the copper complex. The nylon yarn produced has aresistivity of 10 ohms.

The foregoing detailed description has been given for clearness ofunderstanding only and no unnecessary limitations are to be understoodtherefrom. The invention is not limited to the exact details shown and,described, for obvious modifications will occur to those skilled in theart.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. The class of chelate complexes having the formula i wherein R, and R,each has 1-6 carbon atoms and is selectedfrom the group consisting ofperhaloalkyl and w-hydroperhaloalkyl; R, and R taken together areperhaloalkylene having 3-6 carbon atoms; M is an element having anatomic number within one of the ranges 21-30, 39-48, 57-80 and 90-94,with the provisos that when the element has an atomic number of 74, itis in the form W0 and when the element has an atomic number of 92, it isin the form U0 2 is one-half the coordination number of M and is aninteger from 1-4; v is the valence state of M and is an integer from1-4', and (zv) is an integer from 0 to l.

2. The chelate complexes of claim R, each are per(chlorofiuoro)alkyl,having an atomic number within the 2-3 and v is 1-3.

3. The chelate complexes of claim 1 wherein R; and R, each areperfluoroalkyl, M is an element having an atomic number within the range26-30, 2 is 2-3 and v is 1-3.

4. The chelate complexes of claim 1 wherein R, and R each arew-hydroperfiuoroaikyl, M is an element having an atomic number withinthe range 26-30, 2 is 2-3 and v is 1-3.

5. The chelate complexes of claim 1 wherein R, and

1 wherein R; and M is an element range 26-30, 2 is R, taken together areperfluoroalkylene having 3-6 carbon atoms, M is an element having anatomic number within the range 26-30, 2 is 2-3 and v is 1-3.

6. Copper bis(pyrazolide-hexafluoroacetone).

7. [Zinc -tris(pyrazolide-hexafluoroacctone)-] -H 8. Ferrictris(pyrazolide-hexafluoroacetone).

9. [Nickel tris(pvrazolide-hexafiuoroacetone)l"-H+.

10. Cobalt tristpyrazolide-hexafluoroacetone).

H. The process for preparing the chelntc complexes of claim 1 whichcomprises the steps of contacting and reacting a metal pyrazolide M(C HN with a kctone R COR with M, R R, and z being as defined in claim 1, ata temperature of 0-200" C., with the molar ratio of said pyrazole tosaid ketone being within the range 1:20 to 20:1, and thereafterrecovering by conventional means from the reaction mixture said chelatecomplex.

References Cited by the Examiner Kostyanovskii, Doklady Akademic NaukSSSR, vol. 139, pp. 877-879 (August 1961).

HENRY R. JILES, Primary Examiner.

R. I. GALLAGHER, Assistant Examiner.

1. THE CLASS OF CHELATE COMPLEXES HAVING THE FORMULA MULA
 11. THEPROCESS FOR PREPARING THE CHELATE COMPLEXES OF CLAIM 1 WHICH COMPRISESTHE STEPS OF CONTACTING AND REACTING A METAL PYRAZOLIDE M(C3H3N2)Z WITHA KETONE RFCORF'', WITH M, RF, RF'' AND Z BEING AS DEFINED IN CLAIM 1,AT A TEMPERATURE OF 0-200*C., WITH THE MOLAR RATIO OF SAID PYRAZOLE TOSAID KETONE BEING WITHIN THE RANGE OF 1:20 TO 20:1, AND THEREAFTERRECOVERING BY CONVENTIONAL MEANS FROM THE REACTION MIXTURE SAID CHELATECOMPLEX.